Originally published on KSU Swine Day, Volume 1, Issue 7
Introduction
The proper vitamin and trace mineral supplementation required to optimize performance, but also minimize unnecessary cost, is an area of limited knowledge for production nutritionists. Most commercial diets are formulated well above NRC requirement estimates to maintain a margin of safety needed with potential ingredient ...

Large differences in the values of vitamin and trace element supplements (especially the latter) are not unexpected. 1. the NRC requirements are set with a view to ensuring minimum physiological needs. However, they are not justified precisely enough, which is probably not possible ( see: - Underwood and Suttle, 1999, and many others). 2. It is impossible to choose any single criterion, which confirms the optimal level. 3. Important background feeding, which is used to determine the norms of the need for trace elements.Therefore, in specific cases, researchers and practitioners may be right, but their results cannot be extended to all cases. Similar work was carried out in 2002 by company "Provimi" , and we came to similar conclusions (the results were not published – it was official material).Unfortunately, this is a reality to accept, and of course, as often in life, mistakes are not excluded.

I often find that levels of vitamins are driven higher each year by the Vitamin Supply Companies in Europe and Inorganic Trace Element levels of some Trace Elements are driven lower to be replaced with Organics. Is this sound advice to be doing this or is this being driven for continual profit seeking?

First on the trace minerals: commercial diets contain margins of safety for trace minerals and vitamins. The extra trace minerals had increased over time. Data started being published suggesting that the excess trace minerals may be negative for productivity along with being a potential environmental concern. Thus, the levels have been reducing to be closer to requirements. You are correct that organic minerals also have led some of this reduction.

Vitamins are a more difficult one because higher levels of some vitamins can impact blood parameters or immune function and there is less negative impact of feeding high levels, other than cost. Thus, it is easier to find research showing benefits of higher levels of a particular vitamin on particular metabolic outcomes. These outcomes are often not tied to pig performance, mortality, or economics, so you are right to be skeptical. The relatively low cost of vitamins for a commercial production system also puts them on the low end of priority scale for devoting resources to testing in large scale studies, which are needed to truly document economic benefit to marginal increases in particular vitamins. Thus, dietary levels for individual vitamins are based on history, risk tolerance, and differing opinions on the limited data.